Table 1
Characteristics of eligible workers, by case status
| Characteristic | Bladder cancer cases (n=50)* | Other cohort members (n=1762) | Test for difference |
|---|---|---|---|
| Gender | |||
| Male, n (%) | <50† | 1629 (92) | |
| Female, n (%) | <5† | 133 (8) | Fisher's exact p=0.17 |
| Race | |||
| White, n (%) | 34 (68) | 715 (41) | |
| Non-white, n (%) | 0 | 76 (4) | |
| Unknown, n (%)‡ | 16 (32) | 971 (55) |  p=0.0004 |
| Year of birth | |||
| Median (range) | 1932 (1914–1956) | 1948 (1891–1979) | Wilcoxon p<0.0001 |
| Duration of employment (years)§ | |||
| Mean (SD) | 20.4 (11.0) | 8.1 (11.7) | |
| Median (range) | 22.0 (0.3–37.5) | 1.4 (0.005–45.5) | Wilcoxon p<0.0001 |
| Cumulative rank (unit-years)§ | |||
| Mean (SD) | 100.0 (74.6) | 28.2 (49.8) | |
| Median (Range) | 78.5 (0.8–296.7) | 4.4 (0–296.9) | Wilcoxon p<0.0001 |
| Exposure group | |||
| Probably not exposed, n (%) | 5 (10) | 557 (32) | |
| Probably exposed (low and irregularly/occasionally), n (%) | 5 (10) | 150 (9) | |
| Probably exposed (low and regularly), n (%) | 5 (10) | 190 (11) | |
| Definitely exposed (moderate/high), n (%) | 35 (70) | 865 (49) | χ23df p=0.0083 |
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*Cases included ICD-O codes 8010, 8070, 8120, 8130 and 8140. They included 38 malignant/invasive cancers and 14 urothelial carcinoma in situ or non-invasive papillary urothelial carcinoma (<5 in this last category).
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†Counts in individual cells with fewer than 5 observations, or where fewer than 5 observations can be inferred, were not provided, to protect worker confidentiality.
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‡Race/ethnicity was not available for some cohort members. For the analysis, race was assumed to be Caucasian, based on demographics in the geographic area.
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§Duration of employment and cumulative rank through date of diagnosis for cases.
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ICD, International Classification of Diseases.